Subsequent Events	9 Months Ended
Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	NOTE 13 – SUBSEQUENT EVENT On October 1, 2018, pursuant to the Agreement and Plan of Merger, dated as of June 11, 2018 (the “Merger Agreement”), by and between CapStar Financial Holdings, Inc., a Tennessee corporation (“CapStar”), and Athens Bancshares Corporation, a Tennessee corporation (“Athens”), Athens was merged with and into CapStar, with CapStar continuing as the surviving entity (the “Merger”). Immediately following the Merger, Athens Federal Community Bank, National Association, a wholly owned subsidiary of Athens, merged with and into CapStar Bank, a wholly owned subsidiary of CapStar (the “Bank Merger”), with CapStar Bank continuing as the surviving entity in the Bank Merger. On the terms and subject to the conditions set forth in the Merger Agreement, at the effective time of the Merger (the “Effective Time”), each share of common stock, par value $0.01, of Athens (“Athens Common Stock”) issued and outstanding immediately prior to the completion of the merger (other than dissenting shares and shares of Athens common stock owned directly or indirectly by Athens, CapStar and their wholly owned subsidiaries (in each case, other than shares of Athens common stock held in a fiduciary capacity or in connection with debts previously contracted) was converted into the right to receive 2.864 shares (the “Exchange Ratio”) of voting common stock, par value $1.00 per share, of CapStar (“CapStar Common Stock”), with cash paid in lieu of fractional shares. This resulted in the issuance of 5,181,916 shares of CapStar common stock on October 1, 2018. At the Effective Time, each outstanding and unexercised Athens stock option granted under the Athens Bancshares Corporation 2010 Equity Incentive Plan (the “Athens Equity Plan”) that was held by an employee or service provider of Athens who had terminated service prior to the Effective Time was cancelled and converted into the right to receive the cash value of the merger consideration (determined in accordance with the terms of the Merger Agreement), less the applicable option exercise price and less applicable withholding taxes. Except as described in the prior sentence, each outstanding and unexercised Athens stock option granted under the Athens Equity Plan was converted into an option to purchase shares of CapStar Common Stock, with the number of shares and exercise price adjusted to reflect the Exchange Ratio in accordance with the terms of the Merger Agreement. The converted options resulted in the right to purchase 548,051 shares of CapStar Common Stock at a weighted average exercise price of $5.06. Total acquisition consideration resulting from the Merger amounted to approximately $92.9 million. The foregoing description of the Merger Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the Merger Agreement, a copy of which was attached as Exhibit 2.1 to CapStar’s Form 8-K filed with the U.S. Securities and Exchange Commission on June 14, 2018 and the terms of which are incorporated herein by reference.

NOTE 13 – SUBSEQUENT EVENT

On October 1, 2018, pursuant to the Agreement and Plan of Merger, dated as of June 11, 2018 (the “Merger Agreement”), by and between CapStar Financial Holdings, Inc., a Tennessee corporation (“CapStar”), and Athens Bancshares Corporation, a Tennessee corporation (“Athens”), Athens was merged with and into CapStar, with CapStar continuing as the surviving entity (the “Merger”). Immediately following the Merger, Athens Federal Community Bank, National Association, a wholly owned subsidiary of Athens, merged with and into CapStar Bank, a wholly owned subsidiary of CapStar (the “Bank Merger”), with CapStar Bank continuing as the surviving entity in the Bank Merger.

On the terms and subject to the conditions set forth in the Merger Agreement, at the effective time of the Merger (the “Effective Time”), each share of common stock, par value $0.01, of Athens (“Athens Common Stock”) issued and outstanding immediately prior to the completion of the merger (other than dissenting shares and shares of Athens common stock owned directly or indirectly by Athens, CapStar and their wholly owned subsidiaries (in each case, other than shares of Athens common stock held in a fiduciary capacity or in connection with debts previously contracted) was converted into the right to receive 2.864 shares (the “Exchange Ratio”) of voting common stock, par value $1.00 per share, of CapStar (“CapStar Common Stock”), with cash paid in lieu of fractional shares. This resulted in the issuance of 5,181,916 shares of CapStar common stock on October 1, 2018.

At the Effective Time, each outstanding and unexercised Athens stock option granted under the Athens Bancshares Corporation 2010 Equity Incentive Plan (the “Athens Equity Plan”) that was held by an employee or service provider of Athens who had terminated service prior to the Effective Time was cancelled and converted into the right to receive the cash value of the merger consideration (determined in accordance with the terms of the Merger Agreement), less the applicable option exercise price and less applicable withholding taxes. Except as described in the prior sentence, each outstanding and unexercised Athens stock option granted under the Athens Equity Plan was converted into an option to purchase shares of CapStar Common Stock, with the number of shares and exercise price adjusted to reflect the Exchange Ratio in accordance with the terms of the Merger Agreement. The converted options resulted in the right to purchase 548,051 shares of CapStar Common Stock at a weighted average exercise price of $5.06.

Total acquisition consideration resulting from the Merger amounted to approximately $92.9 million.

The foregoing description of the Merger Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the Merger Agreement, a copy of which was attached as Exhibit 2.1 to CapStar’s Form 8-K filed with the U.S. Securities and Exchange Commission on June 14, 2018 and the terms of which are incorporated herein by reference.